The present invention relates generally to sealed power connectors and feed attachments, such including resilient engagement capability. More particularly, the present invention is directed to an electrical terminal socket which incorporates a hectically wound and compressible spring cage and an encircling tubular shaped and compressible terminal sleeve for holding the spring cage in place. The present assembly provides a low cost solution for a quick connect assembly and which requires a much greater degree of torque control in assembly as opposed to prior art bolt and nut type cable connections. The present invention further discloses variations of xe2x80x9cTxe2x80x9d shaped sealed connection assemblies, and which include the terminal socket assembly enclosed within interengaging male and female outer connecting portions, for better insulating and sealing the electrical connections established by the socket assembly.
Electrical connectors of the terminal socket variety are well known in the art, one primary application of which being in the automotive field for establishing connections between heavier sized output cable and components such as generators or alternators. The frictional grip imparted by the connector must be of sufficient strength to maintain firm mechanical and adequate electrical connection, yet must permit relatively easy manual withdrawal or insertion of a prong into the connector socket.
One type of known prior art electrical cable connection is the bolt-nut type electrical cable connection. A significant problem associated with such bolt and nut arrangements arises from the amount of torque which is necessary to assemble the connector and the difficult quality control issues which arise from its large scale use such as over torque, under torque and cross thread.
Generally, it has also been difficult to manufacture spring cage socket terminals, designed from either a single piece of material or assembled from parts, which may include a plurality of individual connector strips or wires. In instances where the terminal is constructed in one piece, several complex machining and forming steps are required. Additionally, construction of a socket terminal starting with individual contact strips requires a tedious assembly process and involving more than four (4) components. As such, manual assembly involving socket terminals is both an intricate and difficult task, as well as a necessary one, and significantly increases a cost of production associated with the connector.
Another example of a radially resilient terminal socket is set forth in U.S. Pat. No. 4,657,335, issued to Koch, and which teaches constructing a barrel terminal socket by forming a sheet metal blank with uniformly spaced, parallel, longitudinal strips integrally connected at their opposite ends to transversely extending webs. The blank is then formed into a cylinder, inserted into a close-fitting cylindrical sleeve and one end of the blank is fixedly secured to the sleeve. The opposite end of the blank is then rotated relative to the sleeve through a predetermined angle and then fixedly secured in its rotated position to the sleeve. Accordingly, Koch teaches a multiple of individual assembly steps and the use of no less than five (5) separate components, which are necessary to complete the construction of the terminal socket.
U.S. Pat. No. 4,734,063, also issued to Koch, discloses additional, methods and techniques for constructing the barrel terminal, including the contactor strip portions being provided as a plurality of individual and spaced apart blanks attached to a carrier strip (46). Each blank is advanced through a number of work stations and assembled utilizing no less than four (4) components, such varied assembly steps including forming the contactor strips into a hollow barrel configuration and fitting the sleeve onto the barrel configured blank.
In summary, the above two prior art patents each utilize at least four (4) or more components in order to construct a power terminal, the net effect of which is to increase the cost, render more complex the design, and slow processing of the parts. It is further found that the provision of many joints, connecting these components together, decreases the effective contact surface for effecting the electrical communication, and has been found to be less reliable and have more potential failure modes.
In sum, it has been determined that it is important to maintain sufficient contact surface and in order to guarantee that an adequate amount of electrical current is carried through the terminal assembly.
The present invention discloses an electrical terminal socket assembly which incorporates a helically wound and compressible spring cage and an encircling tubular shaped and compressible xe2x80x9cTxe2x80x9d shaped terminal sleeve for holding the spring cage in place. As previously explained, the present assembly provides a low cost solution for a quick connect assembly and which requires a much greater degree of torque control in assembly, as opposed to prior art bolt and nut type cable connections. The present invention is also an improvement over prior art assembly techniques which require the spring cage element to be formed in place after it has been inserted into the corresponding sleeve component, particularly in that the present invention provides only two components and a simplified assembly process. It is further contemplated that the assembly part can be manufactured in conjunction with a fast speed progression die.
A spring cage blank has first and second extending edges and a plurality of spaced apart and angled beams extending between the edges. In a preferred variant, a plurality of the spring cage blanks are provided in spaced fashion between first and second carrier strips and which permit the blanks to be transferred in succession into an appropriate die stamping or forming operation. Such stamping or other suitable forming operation typically includes the provision of first and second spaced apart and opposing mandrels, each further including a substantially cylindrical projection with inwardly sloping walls engaging thereupon the associated extending edges of the spring cage.
In one variant, female die patterns are employed in one or more stamping/forming operation to form the spring cage blank in to a substantially cylindrical configuration and in which the angled beams are arranged in a substantially helix pattern. In a still further variant, the stamping dies are succeeded by alternately configured forming dies, the purpose of which being to grasp the opposite extending edges of a substantially formed spring cage and subsequently to torsionally bend the spring cage a specified angular degree in a direction consistent with the angle established by the beams. Depending upon the configuration of the female die surfaces, and/or the application of the torsional bending step, the formed spring cage may further exhibit a substantially xe2x80x9chourglassxe2x80x9d shape and which will improve its connector biasing qualities in subsequent use.
A substantially tubular shaped and interiorly hollowed sleeve is provided for receiving the substantially cylindrically/hourglass shaped spring cage in axially inserting and fixedly and pressure retaining fashion. The spring cage is typically dimensioned to slidably engage within the axial interior of the tubular sleeve without an excessive amount of effort. The sleeve is in turn typically slitted or otherwise configured so that opposing edges are separated by a specified gap and are capable of being compressingly engaged together. In one preferred variant, meshing keyed portions are defined along the slitted and gapped surface and so that, upon inserting assembly of the formed spring cage, the exterior surface of the sleeve is compressingly engaged (such as again through the employed of stamping dies or other suitable manufacturing operation) and in order to create a desired interference fit between the spring cage and the interior of the sleeve.
The interference fit created between the spring cage and sleeve provides the primary retaining feature of the terminal socket assembly. Additionally however, a lance is associated with a transition area of the tubular sleeve and functions as a cage forward stop. A front dish-like feature is installed after the cage is located in proper position. The front dish-like feature functions as a forward stop and further assists in retaining the cage inside the sleeve. It is again understood that the lance and dish-like feature are supplemental features which assist in retaining the cage inside the tubular sleeve.
In order to complete the electrical connection, an extending end of a male pin is secured within the interiorly hollowed sleeve and assembled spring cage. The sleeve, in any of a number of alternate variants, further includes actuable gripping portions for fixedly engaging against and securing an extending end of a cable. The gripping portions may further be configured so that the cable extends in an angular (typically 90xc2x0) relationship relative to the male pin secured to the sleeve and spring cage assembly.
As is particularly disclosed in the present application, assembly configurations of the quick connect socket assembly disclose variations of xe2x80x9cTxe2x80x9d shaped sealed assemblies. Also, sealed housing assemblies disclosed by the present invention include interengaging male and female outer connecting portions and associated seals and retainers, for electrically and environmentally sealing and insulating the socket assembly and extending cables.